4-(Trifluoromethoxy)aniline → (5SR,6RS)-8-benzyl-6-hydroxy-2-(4-trifluoromethoxy-phenyl)-2,8-diaza-spiro[4.5]decan-1-one

Participants

Reaction Steps

To a solution of (3RS,4SR)-1-benzyl-3-hydroxy-4-(2-methoxy-ethyl)-piperidine-4-carboxylic acid ethyl ester (618 mg, 1.92 mmol) and 4-(trifluoromethoxy)aniline (516 μL, 3.85 mmol) in toluene (5 ml) under an argon atmosphere at room temperature, was added dimethylaluminium chloride (0.9M solution in heptane, 4.27 ml, 3.85 mmol) and the mixture was refluxed for 4 hours. The reaction mixture was cooled to room temperature and quenched with sat. Na2SO4 (aq) solution and the mixture was filtered through Celite® and evaporated under reduced pressure. The crude residue was purified by flash column chromatography (1:1 AcOEt/heptane) to give (5SR,6RS)-8-benzyl-6-hydroxy-2-(4-trifluoromethoxy-phenyl)-2,8-diaza-spiro[4.5]decan-1-one (620 mg, 77%) as a white solid. MS (ESI): 405.4 (MH+).

Provenance & Evidence